Note: Unless you are using a severely outdated operating system or CPU, you most likely want to always download the x64 (64-bit) version of Ultimate Doom Builder.
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
The 64-bit version has less limitations on the total size of the project that you can load and edit, while the x86 (32-bit) version of Ultimate Doom Builder only exists for compatibility with older PCs.
If not sure, follow these instructions to find out whether your system is 64-bit: Which version of Windows operating system am I running?
All recent versions
Ultimate Doom Builder R4260
09 Dec 2025
Ultimate Doom Builder R4259
08 Dec 2025
Fixed build targets for unit tests
Ultimate Doom Builder R4256
30 Nov 2025
Fixed an issue where attenuated lights were not rendered in Visual Mode unless Visual Mode was entered at least once while fog rendering was enabled. Fixes #1263
Ultimate Doom Builder R4255
30 Nov 2025
Added game configurations for UZDoom Doom, Heretic, and Hexen (all UDMF)
Ultimate Doom Builder R4253
20 Nov 2025
Fixed an issue where the MBF21 thing and linedef flags were not copied when copying things and linedefs in the MBF21 game configuration. Fixes #1262
Added unit tests for the CVARINFO parser